The present invention relates to a method of manufacturing a semiconductor device, a semiconductor device, a circuit board, and an electronic instrument.
In recent years, a package for a semiconductor device suitable for high-density mounting has been demanded accompanying a reduction of the size of an electronic instrument. To deal with this demand, a surface-mount package such as a ball grid array (BGA) or a chip scale/size package (CSP) has been developed. In the surface-mount package, a substrate on which an interconnect pattern to be connected with a semiconductor chip is formed may be used.
As a conventional surface-mount package, a semiconductor device in which a semiconductor chip is secured to an interconnect pattern of a substrate using an adhesive sheet such as an anisotropic conductive film (ACF; also called “anisotropic conductive sheet”) or a non-conductive film (NCF) has been known (see Japanese Patent Application Laid-open No. 2003-31602, for example).
In a conventional method of manufacturing a semiconductor device, when covering an interconnect pattern on a substrate with an adhesive sheet, it is difficult to prevent air from entering between the interconnect pattern on the substrate and the adhesive sheet and forming voids. It is also difficult to prevent occurrence of cracks in the adhesive sheet due to expansion of voids by heating for curing the adhesive sheet or for reflowing. It is also difficult to prevent migration of the interconnect pattern due to occurrence of cracks and entrance of moisture.